He loves Pineapples, so get a basement grow pineapples and present them in summer.
You can not have a child with Kai in Harvest Moon DS. But I'm guessing you're talking about Harvest Moon DS Cute, and yes you can have a child after you marry him.
Pineapple.
Kai's Birthday Is Summer 22.The best Gift to give him is a Pineapple.
Go to Ushi No Tane, they'll tell you all you need to know about harvest moon cute :)
It is random. There are five different coloring of children and you can have anyone of them if you marry Kai.
Kai is the only charactor which he LOVES pineapples.
I'm no expert but I've been giving Kai tons of gifts/things he likes and it seems to be working. Try it and see how it works for you! Good luck!
Kai loves pineapple and also likes some easy things to get like bread, oil, wine and eggs.(You can buy those from the supermarket. Pineapple seeds can be bought at the sprite tree)
Kai's favorite thing is pineapple. You need to grow it in the summer. You can get the seeds from the casino for medals. Keep on giving him this and visit everyday and buy something! Hope it helped! :)
Keep Kai very happy and in a season or more after you get married you will find out your character is pregnant. About 60 days later the child will be born.
No he won't his AP will stay the same,they won't go up or down.
To go to the Starry Night Festival with Kai, you must have the affection heart color green, purple or red.